1. Field of the Invention
The present invention is directed to an instant position finder and course plotter which may be used in combination with a navigational chart or map to determine an individual's exact location.
2. Description of the Prior Art
A few navigational aids are available in the prior art which attempt to enable an individual to determine his position. For example, the Endo patent, U.S. Pat. No. 3,859,731 discloses an instrument for determining the position from which a two-dimensional photograph was taken. The instrument includes three verniers III.sub.1, III.sub.2, and III.sub.3, which are rotatably mounted about the center P. By aligning the three verniers with three points a, b and c on a photograph, and thereafter fixing the three verniers relative to each other, an individual may determine the position of a camera which took the photograph by positioning the instrument on a map or chart and aligning the verniers with the reference point A, B and C.
Another prior art instrument is disclosed in the Herrick patent, U.S. Pat. No. 2,679,105, for relocating a position. The instrument 10 includes three arms 34, 44 and 46 pivoted about the element 26.
Further, a number of navigational aids are available in the prior art which use mirrors to locate objects. For example, the Chas patent, U.S. Pat. No. 3,410,642, discloses an instrument for determining the position of a ship. This disclosure includes a movable mirror 10 which is used to superimpose the image of a center object with the image of a right and left object. However, the Chas patent does not disclose a base portion which is calibrated in degrees nor does it disclose the use of a scale positioned along the arms of the instrument. in addition, the mirrors disclosed by Chas are not arranged in the same manner as the sextant type mirrors of the present invention.
The Rolefson patent, U.S. Pat. No. 3,822,480 discloses a position locator or homing device for use by a fisherman. Although the Rolefson patent enables an individual to simultaneously view three landmarks, it does not disclose the specific combination of elements set forth in the present invention.
The disadvantages of the prior art navigational aids are overcome by the instant position finder and course plotter of the present invention. More particularly, the first embodiment of the present invention includes a circular central portion with a fixed center arm and a movable left and right arm. The movable left and right arm are mounted on the circular base member by a center pivot which also functions as a rear sight. Further, a sight is mounted at the outermost extremity of each of the arms. An individual may readily use the instant position finder and course plotter of the present invention by aligning the center arm with a visible charted object. Subsequently, the individual would move the left and right arms to align them with adjacent charted objects positioned to the left and right of the center object. After the instrument is properly aligned on the chart using the observed objects an individual would then have his instant position on the chart at the apex of the pivot sight and he may then also determine his relative distance from his next destination or any other chosen point by utilizing a scale positioned along the arms of the instrument appropriate to the scale of the chart in use as taken from the chart legend.
The instant position finder and course plotter of the present invention can measure an angle of up to 90.degree. to the right or left of the center arm for a total of 180.degree.. Further, the circular base portion includes degree markings up to 360.degree. to the left and to the right of the fixed center arm. Therefore, the angular relationship of the arms relative to the fixed center arm may be readily determined.
The second embodiment of the present invention utilizes sextant type mirrors to reflect the right and left objects being viewed onto target mirrors positioned on the apex of the base of the center arm. The center object is sighted over the two target mirrors through a scope mounted at the rear of the instrument thus enabling the user to simultaneously sight all three objects.